Lettuce variety 79-315 rz, drake

ABSTRACT

The present invention relates to a  Lactuca sativa  seed designated 79-315 RZ, which exhibits resistance to downy mildew ( Bremia lactucae ) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight. The present invention also relates to a  Lactuca sativa  plant produced by growing the 79-315 RZ seed. The invention further relates to methods for producing the lettuce cultivar, represented by lettuce variety 79-315 RZ.

RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

This application claims priority to U.S. provisional patent applicationSer. No. 61/707,569, filed Sep. 28, 2012.

The foregoing application, and all documents cited therein or duringtheir prosecution (“appln cited documents”) and all documents cited orreferenced in the appln cited documents, and all documents cited orreferenced herein (“herein cited documents”), and all documents cited orreferenced in herein cited documents, together with any manufacturer'sinstructions, descriptions, product specifications, and product sheetsfor any products mentioned herein or in any document incorporated byreference herein, are hereby incorporated herein by reference, and maybe employed in the practice of the invention. More specifically, allreferenced documents are incorporated by reference to the same extent asif each individual document was specifically and individually indicatedto be incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a new lettuce (Lactuca sativa) varietywhich exhibits resistance against downy mildew races B1:1 to B1:28 andCA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII(Bremia lactucae), white colored seeds, an extraordinary high number ofleaves of substantially equal size, and a high winter head weight.

BACKGROUND OF THE INVENTION

All cultivated forms of lettuce belong to the highly polymorphicspecies, Lactuca sativa, which is grown for its edible head and leaves.As a crop, lettuces are grown commercially wherever environmentalconditions permit the production of an economically viable yield.

Lactuca sativa is in the Cichoreae tribe of the Asteraceae (Compositae)family. Lettuce is related to chicory, sunflower, aster, scorzonera,dandelion, artichoke and chrysanthemum. Sativa is one of about 300species in the genus Lactuca.

Lettuce cultivars are susceptible to a number of pests and diseases suchas downy mildew (Bremia lactucae). Every year this disease results inmillions of dollars of lost lettuce crop throughout the world. Downymildew (Bremia lactucae) is highly destructive of lettuce grown atrelatively low temperature and high humidity. Downy mildew is caused bya fungus, Bremia lactucae, which can be one of the following strains:NL1, NL2, NL4, NL5, NL6, NL7, NL10, NL12, NL13, NL14, NL15, NL16, B1:17,B1:18, B1:20, B1:21, B1:22, B1:23, B1:24, B1:25, B1:26, B1:27, B1:28(Van Ettekoven, K. et al., “Identification and denomination of ‘new’races of Bremia lactucae,” In: Lebeda, A. and Kristkova, E (eds.),Eucarpia Leafy Vegetables, 1999, Palacky University, Olomouc, CzechRepublic, pp. 171-175; Van der Arend et al. “Identification anddenomination of “new” races of Bremia lactucae in Europe by IBEB until2002.” In: Van Hintum, Th et al. (eds.), Eucarpia Leafy VegetablesConference 2003, Centre for Genetic Resources, Wageningen, TheNetherlands, p. 151; Plantum NL (Dutch association for breeding, tissueculture, production and trade of seeds and young plants), Van der Arendet al. “Identification and denomination of “new” races of Bremialactucae in Europe by IBEB until 2002.” In: Van Hintum, Th et al.(eds.), Eucarpia Leafy Vegetables Conference 2003, Centre for GeneticResources, Wageningen, The Netherlands, p. 151; Plantum NL (Dutchassociation for breeding, tissue culture, production and trade of seedsand young plants); IBEB press release “New race of Bremia lactucae B1:27identified and nominated”, May 2010; Plantum NL (Dutch association forbreeding, tissue culture, production and trade of seeds and youngplants), “New race of Bremia lactucae B1:28 identified and nominated”,March 2011), Ca-I, Ca-IIA, Ca-IIB, Ca-III, Ca-IV (Schettini, T. M.,Legg, E. J., Michelmore, R. W., 1991. Insensitivity to metalaxyl inCalifornia populations of Bremia lactucae and resistance of Californialettuce cultivars to downy mildew. Phytopathology 81(1). p. 64-70), andCa-V, Ca-VI, Ca-VII, Ca-VIII (Michelmore R. & Ochoa. O. “BreedingCrisphead Lettuce.” In: California Lettuce Research Board, Annual Report2005-2006, 2006, Salinas, California, pp. 55-68).

Downy mildew causes pale, angular, yellow areas bounded by veins on theupper leaf surfaces. Sporulation occurs on the opposite surface of theleaves. The lesions eventually turn brown, and they may enlarge andcoalesce. These symptoms typically occur first on the lower leaves ofthe lettuce, but under ideal conditions may move into the upper leavesof the head. When the fungus progresses to this degree, the head cannotbe harvested. Less severe damage requires the removal of more leavesthan usual, especially when the lettuce reaches its final destination.

Although several known lettuce cultivars exhibit resistance againstdowny mildew, irrespective of lettuce type, all the lettuce cultivarsaffected produce a limited number of leaves that generally are ofunequal size and diminished quality with respect to color and shape.This is a distinct disadvantage for processing purposes because leaveseither need to be sorted based on size or they need to be cut to asmaller, more uniform size. The first option requires additional labor,with not all sizes usable. The second option has the disadvantage thatit creates many cut surfaces, which then are subject to wound-inducedbrowning, resulting in a greatly reduced shelf-life.

Citation or identification of any document in this application is not anadmission that such document is available as prior art to the presentinvention.

SUMMARY OF THE INVENTION

While several known lettuce cultivars produce a large number of small,more uniform leaves (U.S. Pat. No. 6,320,104; US patent publication20070022496; US patent publication 20100229255), there still exists aneed for a lettuce variety which has an extraordinary high number ofleaves of substantially equal size, is resistant against downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII and, is capable of producing a highhead weight under winter conditions.

The present invention addresses this need by providing a new type oflettuce (Lactuca sativa) variety, designated 79-315 RZ and alternativelydesignated as “Drake”. Lettuce cultivar 79-315 RZ or “Drake” exhibits acombination traits including resistance to downy mildew (Bremialactucae) races B1:1 to B1:28 and CA-I, CA-IIA, CA-IIB, CA-III, CA-IV,CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary numberof leaves of substantially equal size, and a high winter head weight.

The present invention provides seeds of lettuce cultivar 79-315 RZ,which have been deposited with the National Collections of Industrial,Marine and Food Bacteria (NCIMB) in Bucksburn, Aberdeen AB21 9YA,Scotland, UK and have been assigned NCIMB Accession No. 42049.

In one embodiment, the invention provides a lettuce plant which mayexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinarynumber of leaves of substantially equal size, and a high winter headweight, representative seed of which have been deposited under NCIMBAccession No. 42049.

In one embodiment, the invention provides a lettuce plant which mayexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinarynumber of leaves of substantially equal size, a high winter head weight,and a low nitrate content, representative seed of which have beendeposited under NCIMB Accession No. 42049.

In one embodiment, the invention provides a lettuce plant which mayexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinarynumber of leaves of substantially equal size, and a winter head weightbetween about 245 g and about 310 g, representative seed of which havebeen deposited under NCIMB Accession No. 42049.

In one embodiment, the invention provides a lettuce plant which mayexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinarynumber of leaves of substantially equal size, low nitrate content, and awinter head weight between about 245 g and about 310 g, and preferably,from least preferable to most preferable, between about 250 g and about305 g, between about 255 g and about 300 g, between about 260 g andabout 300 g, between about 265 g and about 295 g, between about 270 gand about 290 g, between about 275 g and about 285 g, representativeseed of which have been deposited under NCIMB Accession No. 42049.

In one embodiment, the invention provides a lettuce plant designated79-315 RZ, representative seed of which have been deposited under NCIMBAccession No. 42049.

In an embodiment of the present invention, there also is provided partsof a lettuce plant of the invention, which may include parts of alettuce plant exhibiting a combination of traits including resistance todowny mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA,CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white coloredseeds, extraordinary number of leaves of substantially equal size, and ahigh winter head weight, or parts of a lettuce plant having any of theaforementioned resistance(s) and a combination of traits including oneor more morphological or physiological characteristics tabulated herein,including parts of lettuce variety 79-315 RZ, wherein the plant partsare involved in sexual reproduction, which include, without limitation,microspores, pollen, ovaries, ovules, embryo sacs or egg cells and/orwherein the plant parts are suitable for vegetative reproduction, whichinclude, without limitation, cuttings, roots, stems, cells orprotoplasts and/or wherein the plant parts are tissue culture ofregenerable cells in which the cells or protoplasts of the tissueculture are derived from a tissue such as, for example and withoutlimitation, leaves, pollen, embryos, cotyledon, hypocotyls, meristematiccells, roots, root tips, anthers, flowers, seeds or stems. The plants ofthe invention from which such parts can come from include those whereinrepresentative seed of which has been deposited under NCIMB AccessionNo. 42049 or lettuce variety or cultivar designated 79-315 RZ, as wellas seed from such a plant, plant parts of such a plant (such as thosementioned herein) and plants from such seed and/or progeny of such aplant, advantageously progeny exhibiting such combination of suchtraits, each of which, is within the scope of the invention; and suchcombination of traits.

In another embodiment there is a plant grown from seeds, representativeseed of which having been deposited under NCIMB Accession No. 42049.

In a further embodiment there is a plant regenerated from theabove-described plant parts or regenerated from the above-describedtissue culture. Advantageously such a plant may have morphologicaland/or physiological characteristics of lettuce variety 79-315 RZ and/orof a plant grown from seed, representative seed of which having beendeposited under NCIMB Accession No. NCIMB 42049—including withoutlimitation such plants having all of the morphological and physiologicalcharacteristics of lettuce variety 79-315 RZ and/or of plant grown fromseed, representative seed of which having been deposited under NCIMBAccession No. NCIMB 42049. Advantageously, such a plant demonstrates thetraits of resistance to downy mildew (Bremia lactucae) races B1:1 toB1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII, white colored seeds, extraordinary number of leaves ofsubstantially equal size, and a high winter head weight.

Accordingly, in still a further embodiment, there is provided a lettuceplant having all of the morphological and physiological characteristicsof lettuce variety 79-315 RZ, representative seed of which having beendeposited under NCIMB Accession No. 42049. Such a plant can be grownfrom the seeds, regenerated from the above-described plant parts, orregenerated from the above-described tissue culture. A lettuce planthaving any of the aforementioned resistance(s), and one or moremorphological or physiological characteristics recited or tabulatedherein, and a lettuce plant advantageously having all of theaforementioned resistances and the characteristics recited and tabulatedherein, are preferred. Parts of such plants—such as those plant partsabove-mentioned—are encompassed by the invention.

In one embodiment, there is provided progeny of lettuce cultivar 79-315RZ produced by sexual or vegetative reproduction, grown from seeds,regenerated from the above-described plant parts, or regenerated fromthe above-described tissue culture of the lettuce cultivar or a progenyplant thereof, representative seed of which having been deposited underNCIMB Accession No. 42049. The progeny may have any of theaforementioned resistance(s), and one or more morphological orphysiological characteristics recited or tabulated herein, and a lettuceplant advantageously having all of the aforementioned resistances andthe characteristics recited and tabulated herein, are preferred.Advantageously, the progeny demonstrate the traits of resistance todowny mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA,CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white coloredseeds, extraordinary number of leaves of substantially equal size, and ahigh winter head weight.

Progeny of the lettuce variety 79-315 RZ may be modified in one or moreother characteristics, in which the modification is a result of, forexample and without limitation, mutagenesis or transformation with atransgene.

In still another embodiment, the present invention provides progeny oflettuce cultivar 79-315 RZ produced by sexual or vegetativereproduction, grown from seeds, regenerated from the above-describedplant parts, or regenerated from the above-described tissue culture ofthe lettuce cultivar or a progeny plant thereof, in which theregenerated plant shows a combination of traits including resistance todowny mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA,CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white coloredseeds, extraordinary number of leaves of substantially equal size, and ahigh winter head weight.

In still a further embodiment, the invention may comprise a method ofproducing a hybrid lettuce seed which may comprise crossing a firstparent lettuce plant with a second parent lettuce plant and harvestingthe resultant hybrid lettuce seed, in which the first parent lettuceplant or the second parent lettuce plant may be a lettuce plant of theinvention, e.g. a lettuce plant having a combination of traits includingresistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I,CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, whitecolored seeds, extraordinary number of leaves of substantially equalsize, and a high winter head weight and one or more morphological orphysiological characteristics tabulated herein, including a lettuceplant of lettuce cultivar 79-315 RZ, representative seed of which havingbeen deposited under NCIMB 42049.

In another embodiment, the invention may comprise producing a lettuceplant having a combination of traits including resistance to downymildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB,CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds,extraordinary number of leaves of substantially equal size, and a highwinter head weight which may comprise: crossing a mother lettuce plantwith a father lettuce plant to produce a hybrid seed; growing saidhybrid seed to produce a hybrid plant; selfing said hybrid plant toproduce F2 progeny seed; growing said F2 progeny seed to produceF2-plants; selecting said F2-plants for exhibiting a combination oftraits including resistance to downy mildew (Bremia lactucae) races B1:1to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII, white colored seeds, extraordinary number of leaves ofsubstantially equal size, and a high winter head weight.

Advantageously the selfing and selection may be repeated; for example atleast once, or at least twice, thrice, four times, five times, six timesor more, to produce F3 or F4 or F5 or F6 or subsequent progeny,especially as progeny from F2 may exhibit the aforementioned combinationof traits, and may be desirable.

In still a further embodiment, the invention may comprise a method ofproducing a lettuce cultivar containing a combination of traitsincluding resistance to downy mildew (Bremia lactucae) races B1:1 toB1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII, white colored seeds, extraordinary number of leaves ofsubstantially equal size, and a high winter head weight.

The invention even further relates to a method of producing lettucewhich may comprise: (a) cultivating to the vegetative plant stage aplant of lettuce variety 79-315 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. NCIMB 42049, and (b) harvestinglettuce leaves or heads from the plant. The invention furthercomprehends packaging the lettuce plants, heads or leaves.

Accordingly, it is an object of the invention to not encompass withinthe invention any previously known product, process of making theproduct, or method of using the product such that Applicants reserve theright and hereby disclose a disclaimer of any previously known product,process, or method. It is further noted that the invention does notintend to encompass within the scope of the invention any product,process, or making of the product or method of using the product, whichdoes not meet the written description and enablement requirements of theUSPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of theEPC), such that Applicants reserve the right and hereby disclose adisclaimer of any previously described product, process of making theproduct, or method of using the product.

It is noted that in this disclosure and particularly in the claims,terms such as “comprises”, “comprised”, and “comprising” and the like(e.g., “includes”, “included”, “including”, “contains”, “contained”,“containing”, “has”, “had”, “having”, etc.) can have the meaningascribed to them in US Patent law, i.e., they are open ended terms. Forexample, any method that “comprises,” “has” or “includes” one or moresteps is not limited to possessing only those one or more steps and alsocovers other unlisted steps. Similarly, any plant that “comprises,”“has” or “includes” one or more traits is not limited to possessing onlythose one or more traits and covers other unlisted traits. Similarly,the terms “consists essentially of” and “consisting essentially of” havethe meaning ascribed to them in US Patent law, e.g., they allow forelements not explicitly recited, but exclude elements that are found inthe prior art or that affect a basic or novel characteristic of theinvention. See also MPEP §2111.03. In addition, the term “about” is usedto indicate that a value includes the standard deviation of error forthe device or method being employed to determine the value.

These and other embodiments are disclosed or are obvious from andencompassed by the following Detailed Description.

DEPOSIT

The Deposit with NCIMB Ltd, Ferguson Building, Craibstone Estate,Bucksburn, Aberdeen AB21 9YA, UK, on 4 Sep., 2012, under depositaccession number NCIMB 42049 was made pursuant to the terms of theBudapest Treaty. Upon issuance of a patent, all restrictions upon thedeposit will be removed, and the deposit is intended to meet therequirements of 37 CFR §1.801-1.809. The deposit will be maintained inthe depository for a period of 30 years, or 5 years after the lastrequest, or for the effective life of the patent, whichever is longer,and will be replaced if necessary during that period.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawing, in which:

FIG. 1 is an illustration of six different shapes of the fourth leaffrom a 20-day old seedling grown under optimal conditions.

FIG. 2 is a picture of the fourth leaf.

FIG. 3 is a picture of the mature leaf.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides methods and compositions relating to plants,seeds and derivatives of a new lettuce variety herein referred to aslettuce variety 79-315 RZ. Lettuce variety 79-315 RZ is a uniform andstable line, distinct from other such lines.

In a preferred embodiment, the specific type of breeding method employedfor developing a lettuce cultivar is pedigree selection, where bothsingle plant selection and mass selection practices are employed.Pedigree selection, also known as the “Vilmorin system of selection,” isdescribed in Fehr, W., Principles of Cultivar Development, Volume I,MacMillan Publishing Co., which is hereby incorporated by reference.

When pedigree selection is applied, in general selection is firstpracticed among F₂ plants. In the next season, the most desirable F₃lines are first identified, and then desirable F₃ plants within eachline are selected. The following season and in all subsequentgenerations of inbreeding, the most desirable families are identifiedfirst, then desirable lines within the selected families are chosen, andfinally desirable plants within selected lines are harvestedindividually. A family refers to lines that were derived from plantsselected from the same progeny from the preceding generation.

Using this pedigree method, two parents may be crossed using anemasculated female and a pollen donor (male) to produce F₁ offspring.Lettuce is an obligate self-pollination species, which means that pollenis shed before stigma emergence, assuring 100% self-fertilization.Therefore, in order to optimize crossing, a method of misting may beused to wash the pollen off prior to fertilization to assure crossing orhybridization.

Parental varieties are selected from commercial varieties thatindividually exhibit one or more desired phenotypes. Additionally, anybreeding method involving selection of plants for the desired phenotypemay be used in the method of the present invention.

The F₁ may be self-pollinated to produce a segregating F₂ generation.Individual plants may then be selected which represent the desiredphenotype in each generation (F₃, F₄, F₅, etc.) until the traits arehomozygous or fixed within a breeding population.

Lettuce variety 79-315 RZ was developed by crossing two lines in aglasshouse in Fijnaart (The Netherlands) in 2007. In the same year, F1plants were grown for F2 seed production, which also took place inFijnaart (The Netherlands). In 2008, an F2 and F3 plant were selectedunder glasshouse conditions in De Lier (The Netherlands). In 2009, an F4plant and subsequent F5 plant were again selected under glasshouseconditions in De Lier (The Netherlands), which was subsequently followedby F6 seed production. In 2010, an F6 and subsequent F7 plant wereselected under glasshouse conditions in 's Gravenzande (TheNetherlands), followed by F8 seed production. In 2011, the F8 line wasestablished to be uniform, and was multiplied under glasshouseconditions in Hoek van Holland (The Netherlands), having seed lot number12R.2938, which was designated as lettuce variety 79-315 RZ and wasgiven the variety name Drake RZ. A representative sample of lettucevariety Drake RZ, also known as 79-315 RZ, was deposited with the NCIMBunder deposit number NCIMB 42049.

In one embodiment, a plant of the invention has all the morphologicaland physiological characteristics of lettuce variety 79-315 RZ. Thesecharacteristics of a lettuce plant of the invention, e.g. variety 79-315RZ, are summarized in Tables 1, 2, and 3.

Next to the morphological and physiological characteristics mentioned inTables 1, 2, and 3, a plant of the invention also exhibits resistance todowny mildew (Bremia lactucae Regel.).

As used herein resistance against Bremia lactucae is defined as theability of a plant to resist infection by each of the various strainsB1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII of Bremia lactucae Regel. in all stages between the seedlingstage and the harvestable plant stage. B1:1 to B1:28 means strains NL1,NL2, NL4, NL5, NL6, NL7, NL10, NL12, NL13, NL14, NL15, NL16, B1:17,B1:18, B1:20, B1:21, B1:22, B1:23, B1:24, B1:25, B1:26, B1:27, B1:28(Van Ettekoven K, Van der Arend A J M, 1999. identification anddenomination of ‘new’ races of Bremia lactucae. In: Lebeda A, KristkovaE (eds.) Eucarpia leafy vegetables '99. Palacky University, Olomouc,Czech Republic, 1999: 171-175; Van der Arend, A. J. M., Gautier, J.,Guenard, M., Michel, H., Moreau, B., de Ruijter, J., Schut, J. W. and deWitte, I. (2003). Identification and denomination of ‘new’ races ofBremia lactucae in Europe by IBEB until 2002. In: Eucarpia leafyvegetables 2003. Proceedings of the Eucarpia Meeting on leafy vegetablesgenetics and breeding. Noorwijkerhout, The Netherlands. Eds. Van HintumT., Lebeda A., Pink D., Schut J. pp 151-160; Van der Arend A J M,Gautier J, Grimault V, Kraan P, Van der Laan R, Mazet J, Michel H, SchutJ W, Smilde D, De Witte I (2006) Identification and denomination of“new” races of Bremia lactucae in Europe by IBEB until 2006;incorporated herein by reference; Plantum NL (Dutch association forbreeding, tissue culture, production and trade of seeds and youngplants), IBEB press release, “New race of Bremia lactucae B1:27identified and nominated”, May 2010; Plantum NL (Dutch association forbreeding, tissue culture, production and trade of seeds and youngplants), IBEB press release, “New race of Bremia lactucae B1:28identified and nominated”, March 2011). CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII means Ca-I, Ca-IIA, Ca-IIB, Ca-III,Ca-IV (Schettini, T. M., Legg, E. J., Michelmore, R. W., 1991.Insensitivity to metalaxyl in California populations of Bremia lactucaeand resistance of California lettuce cultivars to downy mildew,Phytopathology 81(1). p. 64-'70), and Ca-V, Ca-VI, Ca-VII, Ca-VIII(Michelmore R. & Ochoa. O. “Breeding Crisphead Lettuce.” In: CaliforniaLettuce Research Board, Annual Report 2005-2006, 2006, Salinas,California, pp. 55-68).

Resistance typically is tested by two interchangeable methods, describedby Bonnier, F. J. M. et al. (Euphytica, 61(3):203-211, 1992;incorporated herein by reference). One method involves inoculating 7-dayold seedlings, and observing sporulation 10 to 14 days later. The othermethod involves inoculating leaf discs with a diameter of 18 mm obtainedfrom a non-senescent, fully grown true leaf and observing sporulation 10days later.

As used herein, an extraordinary high leaf number is the leaf number ofa lettuce plant which is at least about two times to about four times ashigh as the leaf number of a plant of a regular lettuce variety grown inthe same environment during the same period of time. The observation ofleaf number should be done at the plant stage where the above-ground drymatter is between 100 and 400 grams, and before the plant starts tobolt.

As used herein, a multileaf lettuce plant is a lettuce plant with anextraordinary high leaf number. This is caused by a single recessivegenetic factor, which is present in the plant in a homozygous state.

In Table 1, the seed color, cotyledon shape and characteristics of thefourth leaf of “79-315 RZ” is compared with “Cook” and “Salad Bowl”.

TABLE 1 Character “79-315 RZ” “Cook RZ” “Salad Bowl” Plant TypeCutting/leaf Cutting/leaf Cutting/leaf Seed Color White Black BlackCotyledon Shape Intermediate Intermediate Intermediate Shape of FourthElongated Elongated Pinnately lobed Leaf Rolling of Fourth PresentPresent Present Leaf Cupping of Fourth Uncupped Uncupped Uncupped LeafFourth Leaf Apical Entire Entire Lobed Margin Fourth Leaf Basal CoarselyCoarsely Lobed Margin dentate dentate Undulation Slight to fiat SlightSlight to fiat Green color Medium green Medium green Yellow green todark to dark Anthocyanin Absent Absent Absent distribution

In Table 2, the mature leaf and bolting characteristics of “79-315 RZ”is compared with “Cook” and “Salad Bowl”. RHS=Royal Horticulural Societycolour chart code.

TABLE 2 Character “79-315 RZ” “Cook” “Salad Bowl” Leaf Color Mediumgreen Medium green Medium green to dark to yellowish Anthocyanin AbsentAbsent Absent Distribution Margin Incision Moderate Moderate ModerateDepth to shallow to shallow to deep Margin Shallowly Shallowly ShallowlyIndentation dentate dentate dentate Undulations of Moderate ModerateModerate the Apical Margin to slight Leaf Size Small Small Medium tolarge Leaf Glossiness Moderate to Moderate to Moderate dull dull LeafBlistering Absent to slight Absent to slight Slight to moderate LeafThickness Thin Thin Thin Trichomes Absent Absent Absent Bolting classRapid Slow Medium Bolter leaves Straight Curved to slight Curved Colorof the Medium to Dark to Light green bolter leaves dark green mediumgreen

As used herein, winter conditions is to mean outdoor conditions for awinter production area for lettuce having an average daily temperatureof the coldest month between 11 and 14 degrees Celcius, as is the casefor example for Cartagena, Spain or Yuma, USA. The growing cycle underthese conditions should be at least 16 weeks from the time seeds aresown until mature plants are harvested. Harvesting the mature plantshould take place in the month after the coldest month.

As used herein winter head weight is defined as the average weight often heads at the harvest stage, grown under winter conditions.

As used herein, a high winter head weight is defined as a winter headweight that is equal to, or higher than, the standard multileaf lettucevariety Dagama RZ.

The lettuce plant of the invention has a winter head weight betweenabout 245 g and about 310 g, and preferably, from least preferable tomost preferable, between about 250 g and about 305 g, between about 255g and about 300 g, between about 260 g and about 300 g, between about265 g and about 295 g, between about 270 g and about 290 g, betweenabout 275 g and about 285 g.

In Table 3, the average head weight at harvest stage of three varietiesgrown under winter conditions, are shown. Lettuce variety 79-305 RZ isthe variety of the invention. Lettuce variety Dagama RZ and lettucevariety Cook RZ are used as comparison varieties.

TABLE 3 Variety Winter head weight (g) Dagama RZ 265 (Large) Cook RZ 205(Small) 79-315 RZ (Drake RZ) 280 (Large)

Nitrate is considered as an undesirable nutrient component in our food.Most of the nitrate we take in comes from vegetables, especially leafyvegetables such as lettuce. Lettuce contains relatively high nitratecontents (European Union—Reports of the Scientific Committee for Food,38th series, Opinion of the Scientific Committee for Food on nitratesand nitrite, p. 1-33).

As used herein, a low nitrate content is a nitrate content of theharvested lettuce head which is lower or equal to the nitrate content ofthe harvested lettuce head of the standard multileaf lettuce varietyDescartes (79-154 RZ). As nitrate is strongly influenced by nitrogenavailability (soil, water) and growing conditions, a low nitrate contentof the harvested lettuce head is not defined in absolute figures, but ona relative scale compared with a standard variety grown side-by-side,under the same growing conditions, and in the same growing cycle.

Embodiments of the inventions advantageously have one or more, and mostadvantageously all, of these characteristics.

In an embodiment, the invention relates to lettuce plants that has allthe morphological and physiological characteristics of the invention andhave acquired said characteristics by introduction of the geneticinformation that is responsible for the characteristics from a suitablesource, either by conventional breeding, or genetic modification, inparticular by cisgenesis or transgenesis. Cisgenesis is geneticmodification of plants with a natural gene, coding for an (agricultural)trait, from the crop plant itself or from a sexually compatible donorplant. Transgenesis is genetic modification of a plant with a gene froma non-crossable species or a synthetic gene.

Just as useful traits may be introduced by backcrossing, useful traitsmay be introduced directly into the plant of the invention, being aplant of lettuce variety 79-315 RZ, by genetic transformationtechniques; and, such plants of lettuce variety 79-315 RZ that haveadditional genetic information introduced into the genome or thatexpress additional traits by having the DNA coding there for introducedinto the genome via transformation techniques, are within the ambit ofthe invention, as well as uses of such plants, and the making of suchplants.

Genetic transformation may therefore be used to insert a selectedtransgene into the plant of the invention, being a plant of lettucevariety 79-315 RZ or may, alternatively, be used for the preparation oftransgenes which may be introduced by backcrossing. Methods for thetransformation of plants, including lettuce, are well known to those ofskill in the art.

Vectors used for the transformation of lettuce cells are not limited solong as the vector can express an inserted DNA in the cells. Forexample, vectors which may comprise promoters for constitutive geneexpression in lettuce cells (e.g., cauliflower mosaic virus 35Spromoter) and promoters inducible by exogenous stimuli may be used.Examples of suitable vectors include pBI binary vector. The “lettucecell” into which the vector is to be introduced includes various formsof lettuce cells, such as cultured cell suspensions, protoplasts, leafsections, and callus. A vector may be introduced into lettuce cells byknown methods, such as the polyethylene glycol method, polycationmethod, electroporation, Agrobacterium-mediated transfer, particlebombardment and direct DNA uptake by protoplasts. To effecttransformation by electroporation, one may employ either friabletissues, such as a suspension culture of cells or embryogenic callus oralternatively one may transform immature embryos or other organizedtissue directly. In this technique, one would partially degrade the cellwalls of the chosen cells by exposing them to pectin-degrading enzymes(pectolyases) or mechanically wound tissues in a controlled manner.

A particularly efficient method for delivering transforming DNA segmentsto plant cells is microprojectile bombardment. In this method, particlesare coated with nucleic acids and delivered into cells by a propellingforce. Exemplary particles include those which may be comprised oftungsten, platinum, and preferably, gold. For the bombardment, cells insuspension are concentrated on filters or solid culture medium.Alternatively, immature embryos or other target cells may be arranged onsolid culture medium. The cells to be bombarded are positioned at anappropriate distance below the macroprojectile stopping plate. Anillustrative embodiment of a method for delivering DNA into plant cellsby acceleration is the Biolistics Particle Delivery System, which may beused to propel particles coated with DNA or cells through a screen, suchas a stainless steel or Nytex screen, onto a surface covered with targetlettuce cells. The screen disperses the particles so that they are notdelivered to the recipient cells in large aggregates. It is believedthat a screen intervening between the projectile apparatus and the cellsto be bombarded reduces the size of projectiles aggregate and maycontribute to a higher frequency of transformation by reducing thedamage inflicted on the recipient cells by projectiles that are toolarge. Microprojectile bombardment techniques are widely applicable, andmay be used to transform virtually any plant species, including a plantof lettuce variety 79-315 RZ.

Agrobacterium-mediated transfer is another widely applicable system forintroducing gene loci into plant cells. An advantage of the technique isthat DNA may be introduced into whole plant tissues, thereby bypassingthe need for regeneration of an intact plant from a protoplast.Agrobacterium transformation vectors are capable of replication in E.coli as well as Agrobacterium, allowing for convenient manipulations.Moreover, advances in vectors for Agrobacterium-mediated gene transferhave improved the arrangement of genes and restriction sites in thevectors to facilitate the construction of vectors capable of expressingvarious polypeptide coding genes. The vectors have convenientmulti-linker regions flanked by a promoter and a polyadenylation sitefor direct expression of inserted polypeptide coding genes.Additionally, Agrobacterium containing both armed and disarmed Ti genesmay be used for transformation. In those plant strains whereAgrobacterium-mediated transformation is efficient, it is the method ofchoice because of the facile and defined nature of the gene locustransfer. The use of Agrobacterium-mediated plant integrating vectors tointroduce DNA into plant cells, including lettuce plant cells, is wellknown in the art (See, e.g., U.S. Pats. No. 7,250,560 and 5,563,055).

Transformation of plant protoplasts also may be achieved using methodsbased on calcium phosphate precipitation, polyethylene glycol treatment,electroporation, and combinations of these treatments.

A number of promoters have utility for plant gene expression for anygene of interest including but not limited to selectable markers,scoreable markers, genes for pest tolerance, disease resistance,nutritional enhancements and any other gene of agronomic interest.Examples of constitutive promoters useful for lettuce plant geneexpression include, but are not limited to, the cauliflower mosaic virus(CaMV) P-35S promoter, a tandemly duplicated version of the CaMV 35Spromoter, the enhanced 35S promoter (P-e35S), the nopaline synthasepromoter, the octopine synthase promoter, the figwort mosaic virus(P-FMV) promoter (see U.S. Pat. No. 5,378,619), an enhanced version ofthe FMV promoter (P-eFMV) where the promoter sequence of P-FMV isduplicated in tandem, the cauliflower mosaic virus 19S promoter, asugarcane bacilliform virus promoter, a commelina yellow mottle viruspromoter, the promoter for the thylakoid membrane proteins from lettuce(psaD, psaF, psaE, PC, FNR, atpC, atpD, cab, rbcS) (see U.S. Pat. No.7,161,061), the CAB-1 promoter from lettuce (see U.S. Pat. No.7,663,027), the promoter from maize prolamin seed storage protein (seeU.S. Pat. No. 7,119,255), and other plant DNA virus promoters known toexpress in plant cells. A variety of plant gene promoters that areregulated in response to environmental, hormonal, chemical, and/ordevelopmental signals may be used for expression of an operably linkedgene in plant cells, including promoters regulated by (1) heat, (2)light (e.g., pea rbcS-3A promoter, maize rbcS promoter, or chlorophylla/b-binding protein promoter), (3) hormones, such as abscisic acid, (4)wounding (e.g., wun1, or (5) chemicals such as methyl jasmonate,salicylic acid, or Safener. It may also be advantageous to employorgan-specific promoters.

Exemplary nucleic acids which may be introduced to the lettuce varietyof this invention include, for example, DNA sequences or genes fromanother species, or even genes or sequences which originate with or arepresent in lettuce species, but are incorporated into recipient cells bygenetic engineering methods rather than classical reproduction orbreeding techniques. However, the term “exogenous” is also intended torefer to genes that are not normally present in the cell beingtransformed, or perhaps simply not present in the form, structure, etc.,as found in the transforming DNA segment or gene, or genes which arenormally present and that one desires to express in a manner thatdiffers from the natural expression pattern, e.g., to over-express.Thus, the term “exogenous” gene or DNA is intended to refer to any geneor DNA segment that is introduced into a recipient cell, regardless ofwhether a similar gene may already be present in such a cell. The typeof DNA included in the exogenous DNA may include DNA which is alreadypresent in the plant cell, DNA from another plant, DNA from a differentorganism, or a DNA generated externally, such as a DNA sequencecontaining an antisense message of a gene, or a DNA sequence encoding asynthetic or modified version of a gene.

Many hundreds if not thousands of different genes are known and couldpotentially be introduced into a plant of lettuce variety 79-315 RZ.Non-limiting examples of particular genes and corresponding phenotypesone may choose to introduce into a lettuce plant include one or moregenes for insect tolerance, pest tolerance such as genes for fungaldisease control, herbicide tolerance, and genes for quality improvementssuch as yield, nutritional enhancements, environmental or stresstolerances, or any desirable changes in plant physiology, growth,development, morphology or plant product(s).

Alternatively, the DNA coding sequences may affect these phenotypes byencoding a non-translatable RNA molecule that causes the targetedinhibition of expression of an endogenous gene, for example viaantisense- or cosuppression-mediated mechanisms. The RNA could also be acatalytic RNA molecule (i.e., a ribozyme) engineered to cleave a desiredendogenous mRNA product. Thus, any gene which produces a protein or mRNAwhich expresses a phenotype or morphology change of interest is usefulfor the practice of the present invention. (See also U.S. Pat. No.7,576,262, “Modified gene-silencing RNA and uses thereof.”)

U.S. Pats. Nos. 7,230,158, 7,122,720, 7,081,363, 6,734,341, 6,503,732,6,392,121, 6,087,560, 5,981,181, 5,977,060, 5,608,146, 5,516,667, eachof which, and all documents cited therein are hereby incorporated hereinby reference, consistent with the above INCORPORATION BY REFERENCEsection, are additionally cited as examples of U.S. Patents that mayconcern transformed lettuce and/or methods of transforming lettuce orlettuce plant cells, and techniques from these US Patents, as well aspromoters, vectors, etc., may be employed in the practice of thisinvention to introduce exogenous nucleic acid sequence(s) into a plantof lettuce variety 79-315 RZ (or cells thereof), and exemplify someexogenous nucleic acid sequence(s) which may be introduced into a plantof lettuce variety 79-315 RZ (or cells thereof) of the invention, aswell as techniques, promoters, vectors etc., to thereby obtain furtherplants of lettuce variety 79-315 RZ, plant parts and cells, seeds, otherpropagation material harvestable parts of these plants, etc. of theinvention, e.g. tissue culture, including a cell or protoplast, such asan embryo, meristem, cotyledon, pollen, leaf, anther, root, root tip,pistil, flower, seed or stalk.

The invention further relates to propagation material for producingplants of the invention. Such propagation material may comprise interalia seeds of the claimed plant and parts of the plant that are involvedin sexual reproduction. Such parts are for example selected from thegroup consisting of seeds, microspores, pollen, ovaries, ovules, embryosacs and egg cells. In addition, the invention relates to propagationmaterial which may comprise parts of the plant that are suitable forvegetative reproduction, for example cuttings, roots, stems, cells,protoplasts.

According to a further aspect thereof the propagation material of theinvention may comprise a tissue culture of the claimed plant. The tissueculture may comprise regenerable cells. Such tissue culture may bederived from leaves, pollen, embryos, cotyledon, hypocotyls,meristematic cells, roots, root tips, anthers, flowers, seeds and stems.(See generally U.S. Pat. No. 7,041,876 on lettuce being recognized as aplant that may be regenerated from cultured cells or tissue).

Also, the invention comprehends methods for producing a seed of a“79-315 RZ”-derived lettuce plant which may comprise (a) crossing aplant of lettuce variety 79-315 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. NCIMB 42049, with a secondlettuce plant plant and selecting plants exhibiting a combination of thetraits including resistance to downy mildew (Bremia lactucae) races B1:1to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII, white colored seeds, extraordinary number of leaves ofsubstantially equal size, and a high winter head weight, and (b) wherebyseed of a 79-315 RZ-derived lettuce plant forms. Such a method mayfurther comprise (c) crossing a plant grown from 79-315 RZ-derivedlettuce seed with itself or with a second lettuce plant to yieldadditional 79-315 RZ-derived lettuce seed, and selecting plantsexhibiting a combination of the traits including resistance to downymildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB,CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds,extraordinary number of leaves of substantially equal size, and a highwinter head weight, (d) growing the additional 79-315 RZ-derived lettuceseed of step (c) to yield additional 79-315 RZ-derived lettuce plants,and (e) repeating the crossing and growing of steps (c) and (d) for anadditional 3-10 generations to further generate 79-315 RZ-derivedlettuce plants that exhibits a combination of traits includingresistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I,CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, whitecolored seeds, extraordinary number of leaves of substantially equalsize, and a high winter head weight.

The invention further relates to the above methods that may furthercomprise selecting at steps b), d), and e), a 79-315 RZ-derived lettuceplant, exhibiting a combination of traits including resistance to downymildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB,CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds,extraordinary number of leaves of substantially equal size, and a highwinter head weight.

In particular, the invention relates to methods for producing a seed ofa 79-315 RZ-derived lettuce plant which may comprise (a) crossing aplant of lettuce variety 79-315 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. NCIMB 42049, with a secondlettuce plant and (b) whereby seed of a 79-315 RZ-derived lettuce plantforms, wherein such a method may further comprise (c) crossing a plantgrown from 79-315 RZ-derived lettuce seed with itself or with a secondlettuce plant to yield additional 79-315 RZ-derived lettuce seed, (d)growing the additional 79-315 RZ-derived lettuce seed of step (c) toyield additional 79-315 RZ-derived lettuce plants and selecting plantsexhibiting a combination of traits including resistance to downy mildew(Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III,CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinarynumber of leaves of substantially equal size, and a high winter headweight, and a non-heading plant habit, and (e) repeating the crossingand growing of steps (c) and (d) for an additional 3-10 generations tofurther generate 79-315 RZ-derived lettuce plants that exhibit acombination of traits including resistance to downy mildew (Bremialactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV,CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary numberof leaves of substantially equal size, and a high winter head weight.

The invention additionally provides a method of introducing a desiredtrait into a plant of lettuce variety 79-315 RZ which may comprise: (a)crossing a plant of lettuce variety 79-315 RZ, representative seed ofwhich having been deposited under NCIMB Accession No. NCIMB 42049, witha second lettuce plant that may comprise a desired trait to produce F1progeny; (b) selecting an F1 progeny that may comprise the desiredtrait; (c) crossing the selected F1 progeny with a plant of lettucevariety 79-315 RZ, to produce backcross progeny; (d) selecting backcrossprogeny which may comprise the desired trait and the physiological andmorphological characteristic of a plant of lettuce variety 79-315 RZ;and, optionally, (e) repeating steps (c) and (d) one or more times insuccession to produce selected fourth or higher backcross progeny thatmay comprise the desired trait and all of the physiological andmorphological characteristics of a plant of lettuce variety 79-315 RZ,when grown in the same environmental conditions. The invention, ofcourse, includes a lettuce plant produced by this method.

Backcrossing may also be used to improve an inbred plant. Backcrossingtransfers a specific desirable trait from one inbred or non-inbredsource to an inbred that lacks that trait. This may be accomplished, forexample, by first crossing a superior inbred (A) (recurrent parent) to adonor inbred (non-recurrent parent), which carries the appropriate locusor loci for the trait in question. The progeny of this cross are thenmated back to the superior recurrent parent (A) followed by selection inthe resultant progeny for the desired trait to be transferred from thenon-recurrent parent. After five or more backcross generations withselection for the desired trait, the progeny are heterozygous for locicontrolling the characteristic being transferred, but are like thesuperior parent for most or almost all other loci. The last backcrossgeneration would be selfed to give pure breeding progeny for the traitbeing transferred. When a plant of lettuce variety 79-315 RZ,representative seed of which having been deposited under NCIMB AccessionNo. NCIMB 42049, is used in backcrossing, offspring retaining thecombination of traits including resistance to downy mildew (Bremialactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV,CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary numberof leaves of substantially equal size, and a high winter head weight areprogeny within the ambit of the invention. Backcrossing methods may beused with the present invention to improve or introduce a characteristicinto a plant of the invention, being a plant of lettuce variety 79-315RZ. See, e.g., U.S. Pat. No. 7,705,206 (incorporated herein by referenceconsistent with the above INCORPORATION BY REFERENCE section), for ageneral discussion relating to backcrossing.

The invention further involves a method of determining the genotype of aplant of lettuce variety 79-315 RZ, representative seed of which hasbeen deposited under NCIMB Accession No. NCIMB 42049, or a firstgeneration progeny thereof, which may comprise obtaining a sample ofnucleic acids from said plant and detecting in said nucleic acids aplurality of polymorphisms. This method may additionally comprise thestep of storing the results of detecting the plurality of polymorphismson a computer readable medium. The plurality of polymorphisms isindicative of and/or give rise to the expression of the morphologicaland physiological characteristics of lettuce variety 79-315 RZ.

There are various ways of obtaining genotype data from a nucleic acidsample. Genotype data may be gathered which is specific for certainphenotypic traits (e.g. gene sequences), but also patterns of randomgenetic variation may be obtained to construct a so-called DNAfingerprint. Depending on the technique used a fingerprint may beobtained that is unique for hybrid pepper variety 79-315 RZ. Obtaining aunique DNA fingerprint depends on the genetic variation present in avariety and the sensitivity of the fingerprinting technique. A techniqueknown in the art to provide a good fingerprint profile is called AFLPfingerprinting technique (See generally U.S. Pat. No. 5,874,215), butthere are many other marker based techniques, such as RFLP (orRestriction fragment length polymorphism), SSLP (or Simple sequencelength polymorphism), RAPD (or Random amplification of polymorphic DNA)VNTR (or Variable number tandem repeat), Microsatellite polymorphism,SSR (or Simple sequence repeat), STR (or Short tandem repeat), SFP (orSingle feature polymorphism) DArT (or Diversity Arrays Technology), RADmarkers (or Restriction site associated DNA markers) (e.g. Baird et al.PloS One Vol. 3 e3376, 2008; Semagn et al. African Journal ofBiotechnology Vol. 5 number 25 pp. 2540-2568, 29 December, 2006).Nowadays, sequence-based methods are utilizing Single NucleotidePolymorphisms (SNPs) that are randomly distributed across genomes, as acommon tool for genotyping (e.g. Elshire et al. PloS One Vol. 6: e19379,2011; Poland et al. PloS One Vol. 7: e32253; Truong et al. PLoS One Vol.7 number 5: e37565, 2012).

With any of the aforementioned genotyping techniques, polymorphisms maybe detected when the genotype and/or sequence of the plant of interestis compared to the genotype and/or sequence of one or more referenceplants. As used herein, the genotype and/or sequence of a referenceplant may be derived from, but is not limited to, any one of thefollowing: parental lines, closely related plant varieties or species,complete genome sequence of a related plant variety or species, or thede novo assembled genome sequence of one or more related plant varietiesor species. For example, it is possible to detect polymorphisms for thecharacteristic of seed color, by comparing the genotype and/or thesequence of lettuce variety 79-315 RZ with the genotype and/or thesequence of one or more reference plants. The reference plant(s) usedfor comparison in this example may be any of the comparison varietiesCook RZ, Dagama RZ, or Salad Bowl. It is also possible for example, todetect polymorphisms for the multileaf characteristic by comparing thegenotype and/or the sequence of lettuce variety 79-315 RZ with thegenotype and/or the sequence of one or more reference plants. Thereference plant(s) used for comparison may for example be, but is notlimited to, any of the comparison varieties Cook RZ, Dagama RZ, or SaladBowl.

The polymorphism revealed by these techniques may be used to establishlinks between genotype and phenotype. The polymorphisms may thus be usedto predict or identify certain phenotypic characteristics, individuals,or even species. The polymorphisms are generally called markers. It iscommon practice for the skilled artisan to apply molecular DNAtechniques for generating polymorphisms and creating markers.

The polymorphisms of this invention may be provided in a variety ofmediums to facilitate use, e.g. a database or computer readable medium,which may also contain descriptive annotations in a form that allows askilled artisan to examine or query the polymorphisms and obtain usefulinformation.

As used herein “database” refers to any representation of retrievablecollected data including computer files such as text files, databasefiles, spreadsheet files and image files, printed tabulations andgraphical representations and combinations of digital and image datacollections. In a preferred aspect of the invention, “database” refersto a memory system that may store computer searchable information.

As used herein, “computer readable media” refers to any medium that maybe read and accessed directly by a computer. Such media include, but arenot limited to: magnetic storage media, such as floppy discs, hard disc,storage medium and magnetic tape; optical storage media such as CD-ROM;electrical storage media such as RAM, DRAM, SRAM, SDRAM, ROM; and PROMs(EPROM, EEPROM, Flash EPROM), and hybrids of these categories such asmagnetic/optical storage media. A skilled artisan may readily appreciatehow any of the presently known computer readable mediums may be used tocreate a manufacture which may comprise computer readable medium havingrecorded thereon a polymorphism of the present invention.

As used herein, “recorded” refers to the result of a process for storinginformation in a retrievable database or computer readable medium. Forinstance, a skilled artisan may readily adopt any of the presently knownmethods for recording information on computer readable medium togenerate media which may comprise the polymorphisms of the presentinvention. A variety of data storage structures are available to askilled artisan for creating a computer readable medium where the choiceof the data storage structure will generally be based on the meanschosen to access the stored information. In addition, a variety of dataprocessor programs and formats may be used to store the polymorphisms ofthe present invention on computer readable medium.

The present invention further provides systems, particularlycomputer-based systems, which contain the polymorphisms describedherein. Such systems are designed to identify the polymorphisms of thisinvention. As used herein, “a computer-based system” refers to thehardware, software and memory used to analyze the polymorphisms. Askilled artisan may readily appreciate that any one of the currentlyavailable computer-based system are suitable for use in the presentinvention.

Lettuce leaves are sold in packaged form, including without limitationas pre-packaged lettuce salad or as lettuce heads. Mention is made ofU.S. Pat. No. 5,523,136, incorporated herein by reference consistentwith the above INCORPORATION BY REFERENCE section, which providespackaging film, and packages from such packaging film, including suchpackaging containing leafy produce, and methods for making and usingsuch packaging film and packages, which are suitable for use with thelettuce leaves of the invention. Thus, the invention comprehends the useof and methods for making and using the leaves of the lettuce plant ofthe invention, as well as leaves of lettuce plants derived from theinvention. The invention further relates to a container which maycomprise one or more plants of the invention, or one or more lettuceplants derived from a plant of the invention, in a growth substrate forharvest of leaves from the plant in a domestic environment. This way theconsumer may pick very fresh leaves for use in salads. More generally,the invention includes one or more plants of the invention or one ormore plants derived from lettuce of the invention, wherein the plant isin a ready-to-harvest condition, including with the consumer picking hisown, and further including a container which may comprise one or more ofthese plants.

The invention is further described by the following numbered paragraphs:

1. A lettuce plant exhibiting a combination of traits includingresistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I,CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, whitecolored seeds, extraordinary number of leaves of substantially equalsize, and a high winter head weight, representative seed of which havingbeen deposited under NCIMB Accession No. 42049.

2. The lettuce plant of paragraph 1 wherein the winter head weight isbetween about 245 g and about 310 g.

3. The lettuce plant of paragraph 2 wherein the winter head weight is,in the order from least preferable to most preferable, between about 250g and about 305 g, between about 255 g and about 300 g, between about260 g and about 300 g, between about 265 g and about 295 g, betweenabout 270 g and about 290 g, between about 275 g and about 285 g.

4. The lettuce plant of paragraph 1 or paragraph 2 or paragraph 3wherein the plant exhibits a low nitrate content.

5. A lettuce plant designated 79-315 RZ, representative seed of whichhaving been deposited under NCIMB Accession No. 42049.

6. A seed of the plant of paragraph 1.

7. Parts of the plant of paragraph 1 or paragraph 2 or paragraph 3 orparagraph 4, or paragraph 5, wherein said parts of the plant aresuitable for sexual reproduction.

8. Parts of the plant of paragraph 7, wherein said parts are selectedfrom the group consisting of microspores, pollen, ovaries, ovules,embryo sacs and egg cells.

9. Parts of the plant of paragraph 1 or paragraph 2 or paragraph 3 orparagraph 4, or paragraph 5, wherein said parts of the plant aresuitable for vegetative reproduction.

10. Parts of paragraph 9, wherein said parts are selected from the groupconsisting of cuttings, roots, stems, cells and protoplasts.

11. A tissue culture of regenerable cells from the lettuce plant ofparagraph 1.

12. The tissue culture of paragraph 11, wherein said cells orprotoplasts of the tissue culture which are derived from a tissueselected from the group consisting of leaves, pollen, embryos,cotyledon, hypocotyls, meristematic cells, roots, root tips, anthers,flowers, seeds and stems.

13. A progeny of a lettuce plant of paragraph 1 or paragraph 2 orparagraph 3 or paragraph 4 or paragraph 5.

14. The progeny of paragraph 13, wherein said progeny is produced bysexual or vegetative reproduction of said lettuce plant, and whereinsaid progeny exhibits a combination of traits including resistance todowny mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA,CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white coloredseeds, extraordinary number of leaves of substantially equal size, and ahigh winter head weight.

15. A progeny of a lettuce plant of paragraph 5, having all themorphological and physiological characteristics of the lettuce plant ofparagraph 5, representative seed of which having been deposited underNCIMB Accession No. 42049 wherein the morphological and physiologicalcharacteristics are as found in lettuce variety 79-315 RZ,representative seed of which having been deposited under NCIMB AccessionNo. 42049.

16. A progeny of a lettuce plant of paragraph 1 or paragraph 2 orparagraph 3 or paragraph 4, or paragraph 5, representative seed of whichhaving been deposited under NCIMB Accession 42049, and is modified inone or more other characteristics.

17. The progeny of paragraph 16, wherein the modification is effected bymutagenesis.

18. The progeny of paragraph 16, wherein the modification is effected bytransformation with a transgene.

19. A method of producing a hybrid lettuce seed comprising crossing afirst parent lettuce plant with a second parent lettuce plant andharvesting the resultant hybrid lettuce seed, wherein said first parentlettuce plant or said second parent lettuce plant is the lettuce plantof paragraph 1.

20. A hybrid lettuce plant produced by the method of paragraph 19.

21. A method of producing a lettuce cultivar containing a combination oftraits including resistance to downy mildew (Bremia lactucae) races B1:1to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII,CA-VIII, white colored seeds, extraordinary number of leaves ofsubstantially equal size, and a high winter head weight, comprising:crossing a mother lettuce plant with a father lettuce plant to produce ahybrid seed; growing said hybrid seed to produce a hybrid plant; selfingsaid hybrid plant to produce F2 progeny seed; growing said F2 progenyseed to produce F2-plants; selecting said F2-plants for exhibitingresistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I,CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, whitecolored seeds, extraordinary number of leaves of substantially equalsize, and a high winter head weight, and, selfing said selectedF2-plants to produce F3 progeny seed; growing said F3 progeny seed toproduce F3-plants; selecting F3-plants for exhibiting resistance todowny mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA,CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white coloredseeds, extraordinary number of leaves of substantially equal size, and ahigh winter head weight, optionally followed by more selfing andselection steps.

22. A lettuce cultivar produced by the method of paragraph 21.

23. A method for producing lettuce leaves as a fresh vegetablecomprising packaging leaves of a plant of paragraph 1.

24. A method for producing lettuce leaves as a processed food comprisingprocessing leaves of a plant of paragraph 1.

25. One or more lettuce plants of paragraph 1, in a container, forharvest of leaves.

26. A lettuce plant having morphological and/or physiologicalcharacteristics of a lettuce plant, representative seed of which havingbeen deposited under NCIMB Accession No. 42049.

27. The lettuce plant of paragraph 25 having all the morphological andphysiological characteristics of the lettuce plant, representative seedof which having been deposited under NCIMB Accession No. 42049.

28. A method of introducing a desired trait into a plant of lettucevariety 79-315 RZ comprising: (a) crossing a plant of lettuce variety79-315 RZ, representative seed of which having been deposited underNCIMB Accession No. NCIMB 42049, with a second lettuce plant thatcomprises the desired trait to produce F1 progeny; (b) selecting an F1progeny that comprises the desired trait; (c) crossing the selected F1progeny with a plant of lettuce variety 79-315 RZ, to produce backcrossprogeny and (d) selecting backcross progeny comprising the desired traitand the physiological and morphological characteristic of a plant oflettuce variety 79-315 RZ, when grown in the same environmentalconditions. 29. The method of paragraph 28 further comprising (e)repeating steps (c) and (d) one or more times in succession to produceselected fourth or higher backcross progeny that comprise the desiredtrait and all of the physiological and morphological characteristics ofa plant of lettuce variety 79-315 RZ, when grown in the sameenvironmental conditions.

30. A lettuce plant produced by the method of paragraph 28 or paragraph29.

31. A method for producing a seed of a 79-315 RZ-derived lettuce plantcomprising (a) crossing a plant of lettuce variety 79-315 RZ,representative seed of which having been deposited under NCIMB AccessionNo. NCIMB 42049, with a second lettuce plant, and (b) whereby seed of a79-315 RZ-derived lettuce plant form.

32. The method of paragraph 31 further comprising (c) crossing a plantgrown from 79-315 RZ-derived lettuce seed with itself or with a secondlettuce plant to yield additional 79-315 RZ-derived lettuce seed, (d)growing the additional 79-315 RZ-derived lettuce seed of step (c) toyield additional 79-315 RZ-derived lettuce plants, and (e) repeating thecrossing and growing of steps (c) and (d) for an additional 3-10generations to generate further 79-315 RZ-derived lettuce plants.

33. The method of paragraph 31 or 32 further comprising selecting atsteps b), d), and e), a 79-315 RZ-derived lettuce plant, exhibiting acombination of traits including resistance to downy mildew (Bremialactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV,CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary numberof leaves of substantially equal size, and a high winter head weight.

34. A seed produced by the method of paragraph 31, or paragraph 32, orparagraph 33.

35. A method of determining the genotype of a plant of lettuce variety79-315 RZ, representative seed of which has been deposited under NCIMBAccession No. NCIMB 42049, or a first generation progeny thereof,comprising obtaining a sample of nucleic acids from said plant andcomparing said nucleic acids to a sample of nucleic acids obtained froma reference plant, and detecting a plurality of polymorphisms betweenthe two nucleic acid samples, wherein the plurality of polymorphisms areindicative of lettuce variety 79-315 RZ and/or give rise to theexpression of any one or more, or all, of the morphological andphysiological characteristics of lettuce variety 79-315 RZ of paragraph1.

36. The method of paragraph 35 additionally comprising the step ofstoring the results of detecting the plurality of polymorphisms on acomputer readable medium, or transmitting the results of detecting theplurality of polymorphisms.

37. The computer readable medium of paragraph 36.

Having thus described in detail preferred embodiments of the presentinvention, it is to be understood that the invention is not to belimited to particular details set forth in the above description as manyapparent variations thereof are possible without departing from thespirit or scope of the present invention.

What is claimed is:
 1. A lettuce plant exhibiting a combination of traits including resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight, representative seed of which having been deposited under NCIMB Accession No.
 42049. 2. The lettuce plant of claim 1 wherein the winter head weight is between about 245 g and about 310 g.
 3. The lettuce plant of claim 2 wherein the winter head weight is, in the order from least preferable to most preferable, between about 250 g and about 305 g, between about 255 g and about 300 g, between about 260 g and about 300 g, between about 265 g and about 295 g, between about 270 g and about 290 g, between about 275 g and about 285 g.
 4. The lettuce plant of claim 1 wherein the plant exhibits a low nitrate content.
 5. A lettuce plant designated 79-315 RZ, representative seed of which having been deposited under NCIMB Accession No.
 42049. 6. A seed of the plant of claim
 1. 7. Parts of the plant of claim 1, wherein said parts of the plant are suitable for sexual reproduction.
 8. Parts of the plant as claimed in claim 7, wherein said parts are selected from the group consisting of microspores, pollen, ovaries, ovules, embryo sacs and egg cells.
 9. Parts of the plant of claim 1, wherein said parts of the plant are suitable for vegetative reproduction.
 10. Parts as claimed in claim 9, wherein said parts are selected from the group consisting of cuttings, roots, stems, cells and protoplasts.
 11. A tissue culture of regenerable cells from the lettuce plant of claim
 1. 12. The tissue culture as claimed in claim 11, wherein said cells or protoplasts of the tissue culture which are derived from a tissue selected from the group consisting of leaves, pollen, embryos, cotyledon, hypocotyls, meristematic cells, roots, root tips, anthers, flowers, seeds and stems.
 13. A progeny of a lettuce plant of claim
 1. 14. The progeny as claimed in claim 13, wherein said progeny is produced by sexual or vegetative reproduction of said lettuce plant, and wherein said progeny exhibits a combination of traits including resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight.
 15. A progeny of a lettuce plant of claim 5, having all the morphological and physiological characteristics of the lettuce plant of claim 5, representative seed of which having been deposited under NCIMB Accession No. 42049 wherein the morphological and physiological characteristics are as found in lettuce variety 79-315 RZ, representative seed of which having been deposited under NCIMB Accession No.
 42049. 16. A progeny of a lettuce plant of claim 1, representative seed of which having been deposited under NCIMB Accession 42049, and is modified in one or more other characteristics.
 17. The progeny as claimed in claim 16, wherein the modification is effected by mutagenesis.
 18. The progeny as claimed in claim 16, wherein the modification is effected by transformation with a transgene.
 19. A method of producing a hybrid lettuce seed comprising crossing a first parent lettuce plant with a second parent lettuce plant and harvesting the resultant hybrid lettuce seed, wherein said first parent lettuce plant or said second parent lettuce plant is the lettuce plant of claim
 1. 20. A hybrid lettuce plant produced by the method of claim
 19. 21. A method of producing a lettuce cultivar containing a combination of traits including resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight, comprising: crossing a mother lettuce plant with a father lettuce plant to produce a hybrid seed; growing said hybrid seed to produce a hybrid plant; selfing said hybrid plant to produce F2 progeny seed; growing said F2 progeny seed to produce F2-plants; selecting said F2-plants for exhibiting resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight, and, selfing said selected F2-plants to produce F3 progeny seed; growing said F3 progeny seed to produce F3-plants; selecting F3-plants for exhibiting resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight, optionally followed by more selfing and selection steps.
 22. A lettuce cultivar produced by the method of claim
 21. 23. A method for producing lettuce leaves as a fresh vegetable comprising packaging leaves of a plant of claim
 1. 24. A method for producing lettuce leaves as a processed food comprising processing leaves of a plant of claim
 1. 25. One or more lettuce plants of claim 1, in a container, for harvest of leaves.
 26. A lettuce plant having morphological and/or physiological characteristics of a lettuce plant, representative seed of which having been deposited under NCIMB Accession No.
 42049. 27. The lettuce plant of claim 25 having all the morphological and physiological characteristics of the lettuce plant, representative seed of which having been deposited under NCIMB Accession No.
 42049. 28. A method of introducing a desired trait into a plant of lettuce variety 79-315 RZ comprising: (a) crossing a plant of lettuce variety 79-315 RZ, representative seed of which having been deposited under NCIMB Accession No. NCIMB 42049, with a second lettuce plant that comprises the desired trait to produce F1 progeny; (b) selecting an F1 progeny that comprises the desired trait; (c) crossing the selected F1 progeny with a plant of lettuce variety 79-315 RZ, to produce backcross progeny and (d) selecting backcross progeny comprising the desired trait and the physiological and morphological characteristic of a plant of lettuce variety 79-315 RZ, when grown in the same environmental conditions.
 29. The method of claim 28 further comprising (e) repeating steps (c) and (d) one or more times in succession to produce selected fourth or higher backcross progeny that comprise the desired trait and all of the physiological and morphological characteristics of a plant of lettuce variety 79-315 RZ, when grown in the same environmental conditions.
 30. A lettuce plant produced by the method of claim
 28. 31. A method for producing a seed of a 79-315 RZ-derived lettuce plant comprising (a) crossing a plant of lettuce variety 79-315 RZ, representative seed of which having been deposited under NCIMB Accession No. NCIMB 42049, with a second lettuce plant, and (b) whereby seed of a 79-315 RZ-derived lettuce plant form.
 32. The method of claim 31 further comprising (c) crossing a plant grown from 79-315 RZ-derived lettuce seed with itself or with a second lettuce plant to yield additional 79-315 RZ-derived lettuce seed, (d) growing the additional 79-315 RZ-derived lettuce seed of step (c) to yield additional 79-315 RZ-derived lettuce plants, and (e) repeating the crossing and growing of steps (c) and (d) for an additional 3-10 generations to generate further 79-315 RZ-derived lettuce plants.
 33. The method of claim 31 further comprising selecting at steps b), d), and e), a 79-315 RZ-derived lettuce plant, exhibiting a combination of traits including resistance to downy mildew (Bremia lactucae) races B1:1 to B1:28, CA-I, CA-IIA, CA-IIB, CA-III, CA-IV, CA-V, CA-VI, CA-VII, CA-VIII, white colored seeds, extraordinary number of leaves of substantially equal size, and a high winter head weight.
 34. A seed produced by the method of claim
 31. 35. A method of determining the genotype of a plant of lettuce variety 79-315 RZ, representative seed of which has been deposited under NCIMB Accession No. NCIMB 42049, or a first generation progeny thereof, comprising obtaining a sample of nucleic acids from said plant and comparing said nucleic acids to a sample of nucleic acids obtained from a reference plant, and detecting a plurality of polymorphisms between the two nucleic acid samples, wherein the plurality of polymorphisms are indicative of lettuce variety 79-315 RZ and/or give rise to the expression of any one or more, or all, of the morphological and physiological characteristics of lettuce variety 79-315 RZ as claimed in claim
 1. 36. The method of claim 35 additionally comprising the step of storing the results of detecting the plurality of polymorphisms on a computer readable medium, or transmitting the results of detecting the plurality of polymorphisms.
 37. The computer readable medium of claim
 36. 